What exactly is 1 tonne of CO2 ?
We hear it all the time: to limit global warming, we must drastically reduce our carbon dioxide emissions. These emissions come from our various daily activities. This indicator, adopted globally as a reference unit for climate plans, doesn't often mean a lot to most people. We are going to give you some concrete examples here to help you better understand it.
First of all, you may be wondering why 1 tonne of CO2 equivalent is used as a reference. Let’s first point out that greenhouse gases (GHGs) are more than just CO2; methane, water vapour and nitrous oxide also contribute to global warming.1
In order to quantify 1 tonne of greenhouse gases, scientists from the IPCC (Intergovernmental Panel on Climate Change) decided to use 1 tonne of CO2 equivalent as a reference unit. This lets us state for example that 1 tonne of methane is equivalent to 25 tonnes of CO2. This simplifies the calculations for the members of the IPCC and even every person on the planet. However, while the figures are generally more understandable, we still cannot fully appreciate what a kilo or tonne of CO2 means.1
Did you know? On average, each Swiss person emits 5.8 tonnes of CO2 equivalent per year. However, to limit global warming to +2°C by 2050, each person should be restricted to 1.7 tonnes of CO2! 2
In Switzerland, 1 tonne of CO2 equivalent corresponds to:
• A return flight from Zurich to New York for one person in economy class
• The production of 80 kg of beef (taking into account the supply chain as a whole)
• A commute of 7 km (14 km for a round trip) in a petrol car for 1 year
• One year of oil heating for a 50 m2 apartment
It should now be easier for you to visualise consumption as a CO2 equivalent. If you want other examples or if you want to calculate your own CO2 impact, you can always use the calculator of the MyClimate Foundation.3
Sources:
1) https://www.bafu.admin.ch/bafu/en/home.html
2) https://www.goodplanet.org/en/
3) https://www.myclimate.org/
Photo: Phil Noble/Reuters